This application note introduces the characteristics and applications of the STBP120 overvoltage protection device
The STBP120 is an overvoltage protection (OVP) device designed to protect positive input voltages up to +28 V and support currents up to 2 A. It utilizes a built-in low Rds(on) N-channel MOSFET and charge pump to disconnect the application from the power supply in the event of overvoltage, undervoltage, or thermal shutdown. The device is controlled by a microcontroller and provides status information regarding input overvoltage, undervoltage, and thermal conditions.
| Maximum input voltage | +28 V |
|---|---|
| Maximum supported current | 2 A |
| Overvoltage thresholds | 5.375 V, 5.50 V, 5.90 V and 6.02 V |
| Turn-off delay | less than 1.5 us |
| Package type | 10-lead TDFN |
The primary function is to disconnect the application from the power supply as fast as possible to avoid damage to application components when overvoltage occurs.
Unlike Transil diodes which have inaccurate threshold voltages dependent on current and can suffer from high junction temperatures, the STBP120 uses a comparator and MOSFET to disconnect the load without excessive power dissipation.
The device requires only one external component, a 1 uF input capacitor, to improve ESD immunity and stability under input transients conditions.